Question

(x² - 1 ) dy = -2xydx​

Answer 1

$(x^2 - 1 ) dy =-2xydx\\\\\\\dfrac{dy}{y}=\dfrac{-2x}{x^2-1}\ dx\\\\\\\int\dfrac{dy}{y}=\int\dfrac{-2x}{x^2-1}\ dx\\\\\\\ln y+C=-\ln (x^2-1)\\\\\\Cy=(x^2-1)^{-1}\\\\\\y=\dfrac{C}{x^2-1}$